Sandstone (Ferruginous)
Arenite (Iron-rich)
Category
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite (Iron-rich)
Chert (Jasper variety)
Cryptocrystalline quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Red Jasper (Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
Green Chert (Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Conglomerate
Conglomerate
Petrified Wood
Silicified Wood (SiO2)
Glauconitic Sandstone
Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Chalk
Calcium Carbonate (CaCO3)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Sandstone
Clastic Sedimentary Rock (primarily SiO2)
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Amber in Matrix
Succinite (Carbon-based organic polymer)
Agate (Crazy Lace or Eye Agate)
Silicon Dioxide (SiO2)
Quartz (Milky or Druzy Quartz)
Silicon Dioxide (SiO2)
Carnelian Agate
Carnelian (Silicon Dioxide: SiO2)
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
Botryoidal Goethite on Quartz
Goethite (α-Fe3+O(OH)) on Quartz (SiO2)
Chert (often called Flint or Jasper when red)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Pink Jasper)
Microcrystalline Quartz (SiO2)
Bauxite
Al2O3·2H2O (principally composed of gibbsite, boehmite, and diaspore)
Sandstone
Sandstone (lithified quartz arenite, arkose, graywacke, etc. depending on composition)
Leopard Skin Jasper
Rhyolite (Silicon Dioxide with impurities), SiO2
Banded Agate (Tumbled)
Cryptocrystalline Quartz (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Chert (containing Flint and Chalcedony)
Microcrystalline Quartz (SiO2)
Yellow Chalcedony (Agate)
Silicon Dioxide (SiO2)
Tree Agate
Silicon Dioxide (SiO2) with Chlorite inclusions
Chert (Field Stone)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Chert (Flint variety)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Red Jasper
Silicon Dioxide with Iron inclusions (SiO2 + Fe2O3)
Jasper (Green variety)
Silicon Dioxide (SiO₂)
Tree Agate
Silicon Dioxide (SiO2) - Dendritic Agate/Chalcedony
Chert (Common Variety, Jasper)
Microcrystalline Quartz (SiO2)
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Satin Spar (Selenite)
Gypsum (CaSO4·2H2O)
Sandstone
Arenite (composed primarily of SiO2)
Chert (or Flint)
Silicon dioxide (SiO2)
Sandstone (Yellow/Tan Sandstone)
Arenite (primarily Quartz, SiO2)
Limonite and Goethite encrusted Chert/Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)
Ferruginous Chert
Silicon dioxide with iron oxide impurities (SiO2 + Fe2O3)
Orange Calcite
Calcium Carbonate (CaCO3)